1. Technical Field
The invention relates to techniques for managing data backup in computing systems. More specifically, the invention provides a method for planning and controlling the execution of backup tasks in a computing system.
2. Description of the Prior Art
Data backup in computing systems are necessary in order to produce additional copies of the data that may be used to restore the original data in case of a data loss within the computing system. Many different techniques have been developed to optimize the backup procedure. As an example, U.S. Pat. No. 7,103,740 to Colgrove et al. describes a backup method for a multi-class file system, wherein more recently modified data are assigned and/or migrated to higher storage classes and less recently modified data may be migrated at time intervals to lower storage classes. Backup of each of the storage classes may be performed at time intervals. Irrespective of backup method used, crucial questions for system administrators dealing with backup planning/scheduling include: “When will my backup be finished?”—“Will it be finished early enough so that applications will not be constricted?”—“If resources are limited, how can I make sure that at least the most important backups (production backups) will be finished in time?”
In current scheduling systems, users specify a point in time or a time interval when a certain backup is to be started. This specification has to be carried out for every backup. As a rule, the user estimates the probable backup duration to ensure the requested end time is met. Traditional scheduling systems use forward calculation based on expected duration values for executing jobs. Such scheduling systems do not consider general time interval restrictions. Some state of the art backup management systems, such as Veritas, contain a scheduling system which is calendar driven. It calculates the latest start time based on the last backup run and takes the number of files of backup into account. However, current scheduling systems do not control concurrently running backups during backup execution with respect to their workload and execution progress. Improper scheduling of concurrently running backup procedures can result in delays to data backups and a failure of one or more of the backups to meet their expected target end time.
In view of the foregoing, there is a need for a backup management method with a scheduling process furnishing a reliable backup schedule with reduced the expert knowledge to be provided by the user. Moreover, there is a need of a backup management method which assures that in the case of restricted resources at least the most important backup tasks will be accomplished successfully within a predefined backup window.